The present era of computing has introduced an array of small devices that perform a variety of specific functions. Cellular phones, pagers and portable digital assistants are common examples of these. As technology progresses, however, devices will continue to become smaller and more specialized. One class of small device that is beginning to emerge is a tiny, sensor, sometimes known as a “mote” that is often implemented in a networked configuration.
Networked sensor nodes, sometimes referred to as sensor devices, are undergoing significant advances in structure and low power technology. In some applications, sensor nodes may utilize micro-electromechanical systems, or MEMS, technology. Sensor nodes may include more than one component, such as an embedded processor, digital storage, power source, a transceiver, and an array of sensors, environmental detectors, and/or actuators. In some cases, sensor nodes may rely on small batteries, solar-powered cell, or ambient energy for power, and run for long periods of time without maintenance.
Communication characteristics of nodes may be determined by physical design characteristics and intended use scenarios or both. In some applications, sensor nodes may act as a data source, and it may also forward data from other sensors that are out of range of a central station.
The practical applications of such mini-devices range from environmental monitoring to micro-robots capable of performing microscopic scale tasks. While functionality of an individual sensor node may be limited, a grouping of nodes working together can accomplish a range of tasks, including high level tasks. The tasks of a grouping may include operations such as general information gathering, security, industrial monitoring, military reconnaissance, or biomedical monitoring.
The integration of computation, storage, communication, and physical interaction in silicon has shrunk some sensor nodes down to microscopic scales. The ability to create sensors and actuators with IC technology and integrate them with computational logic has created an abundance of low-power, tiny sensor nodes. Combining these tiny sensor nodes with low power wireless communication networks aids in developing economical, distributed sensors networks. The number of sensor nodes used in a network is increasing as their cost decreases and functionality increases. As a result, the sheer volume of data created by sensor networks, particularly distributed sensor networks, is rapidly increasing.